Combination of golang WebSocket and JSON: realizing data transmission and parsing

The combination of golang WebSocket and JSON: realizing data transmission and parsing

In modern Web development, real-time data transmission is becoming more and more important. WebSocket is a protocol used to achieve two-way communication. Unlike the traditional HTTP request-response model, WebSocket allows the server to actively push data to the client. JSON (JavaScript Object Notation) is a lightweight format for data exchange that is concise, easy to read, and easy to parse between different programming languages.

This article will introduce how to use Golang to combine WebSocket and JSON to achieve data transmission and parsing. We will use Golang's built-in packages net/http and github.com/gorilla/websocket to handle WebSocket connections, and encoding/json to parse and generate JSON data.

First, we need to install the gorilla/websocket package. You can install it using the following command:

go get github.com/gorilla/websocket

Next, we can start writing code.

package main

import (
    "encoding/json"
    "fmt"
    "log"
    "net/http"
    "github.com/gorilla/websocket"
)

type Message struct {
    Content string `json:"content"`
}

var upgrader = websocket.Upgrader{
    ReadBufferSize:  1024,
    WriteBufferSize: 1024,
}

func echoHandler(w http.ResponseWriter, r *http.Request) {
    conn, err := upgrader.Upgrade(w, r, nil)
    if err != nil {
        log.Println(err)
        return
    }
    defer conn.Close()

    for {
        // 读取客户端发送的消息
        _, message, err := conn.ReadMessage()
        if err != nil {
            log.Println(err)
            break
        }

        // 解析JSON数据
        var msg Message
        err = json.Unmarshal(message, &msg)
        if err != nil {
            log.Println(err)
            break
        }

        // 输出收到的消息
        fmt.Println("收到消息:", msg.Content)

        // 发送响应消息
        response := Message{
            Content: "你发送的消息是：" + msg.Content,
        }

        // 将响应转换为JSON格式
        jsonResponse, err := json.Marshal(response)
        if err != nil {
            log.Println(err)
            break
        }

        // 发送JSON响应
        err = conn.WriteMessage(websocket.TextMessage, jsonResponse)
        if err != nil {
            log.Println(err)
            break
        }
    }
}

func main() {
    http.HandleFunc("/ws", echoHandler)
    log.Fatal(http.ListenAndServe(":8080", nil))
}

The above code contains a WebSocket processing function echoHandler, which receives the client's WebSocket connection and processes the sending and receiving of messages. Inside the function, we first read the message sent by the client and parse it into a Message structure. We then output the received message, generate the response message, and convert the response into JSON format. Finally, we use conn.WriteMessage to send the JSON response to the client.

In the main function, we register the WebSocket processing function echoHandler to the /ws route and listen to the local 8080 port.

After compiling and running the program, open the WebSocket connection in the browser, and you can send and receive JSON data through JavaScript's WebSocket object. The following is a simple JavaScript code example:

var socket = new WebSocket("ws://localhost:8080/ws");
socket.onopen = function () {
    console.log('连接已打开');
    var message = {
        content: 'Hello Server!'
    };
    socket.send(JSON.stringify(message));
};
socket.onmessage = function (event) {
    console.log('收到服务器的响应：', JSON.parse(event.data));
    socket.close();
};
socket.onclose = function () {
    console.log('连接已关闭');
};

In the above JavaScript code, we create a WebSocket connection and send a JSON data containing the message content when the connection is opened. When the response from the server is received, we parse and print the response message, and close the WebSocket connection.

The above are some sample codes that use Golang to combine WebSocket and JSON to realize data transmission and parsing. By using WebSocket and JSON, we can easily transfer and parse structured data between clients and servers, enabling real-time data interaction. When writing code that works for your specific use case, remember to include necessary error handling and data validation. Hope this article helps you!

The above is the detailed content of Combination of golang WebSocket and JSON: realizing data transmission and parsing. For more information, please follow other related articles on the PHP Chinese website!